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Getting an axle to follow a path
Kurt_Sawitskas
Member Posts: 14 EDU
Hi, I'm trying to model something like a train track with left/right curves. I have the path centerline and the rails are extruded along the path. Now I want to assemble an axle with wheels onto the rails and have it properly follow the path. I have the wheel mated to the top of the rail with a Tangent Mate. But I'm stumped at the next steps for getting the axle to follow the profile! Looking for suggested approaches and/or helpful training lessons. Thanks!
Best Answer
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Kurt_Sawitskas
Member Posts: 14 EDU
OMG! That's amazing. I'd never thought to use edges in a tangent mate (obviously!). Thank you SO much!!
1
Answers
What if you created an extruded vertical surface from the path spline and set the center plane of your axle and that path surface to tangent?
I think you will need to use two mates: One to guide the center of your axis along the center between the two rails, and one rack/pinion mate to rotate the wheels as they move.
Thank you @MDesign and @martin_kopplow. But I could not get these ideas to work.
So here is a screen shot of the simple track and axle. The track is a 2D (flat) track. I have one wheel mated to the top of one track rail with a tangent mate. Can anyone tell me how to get the axle to follow the curve? I need to solve this before I move on to more complex motion studies. Thanks!
Can you make the face of one of the wheels tangent with the face/edge of the track?
@MDesign I tried that exact idea, but it didn't work. The axle/wheel alignment seems to try following the track face, but gets out of alignment and won't repeat. To explain - I used Tangent mate to select the flat face of the nearest wheel, then selected the flat faces of the straight and curved sections of the track. It seems like it might ALMOST work….. but fails.
Can you share a link to your doc to have a go at it?
Yes! Thanks for your offer to help. Do I need your email address to share? Or, how else?
you can dm me here. or if you want others to see it and give it a try… you can just post it here. there's a share button in the top right and you can set permissions accordingly. although EDU might have restrictions that don't allow you to do that.
This is the link Share https://cad.onshape.com/documents/84ccc5962a6702e63d0175be/w/8a8d7c817a60ee96e5e6370b/e/f5e869d9e8399563b9b05d7f?renderMode=0&uiState=67d8cb440afa3440cf5ad88f
still view only…. I'll create some generic stuff
I just tried something very simple. It didn't work. You can see the two surfaces that should mate with Tangent, but the wheel only slides on its axis.
yeah I'm struggling with it too. tried creating a surface and a curve for it to follow and not having much luck
I got it. I'll clean up my model a bit and share the document.
Thank you for your time and effort. I have an idea that I want to try. I'll share with you if it works. Can you think of any other way to manage this besides the tangent mate?
The trick is to use edges with the tangent mate. not surfaces. So you might need to modify something so that you have 1 edge that can touch an edge path.
https://cad.onshape.com/documents/8b3a0843e085d0b48d421d9b/w/f7454d3ea7cd30135bb01453/e/ed7c48e088ad7ed17eb817dd
OMG! That's amazing. I'd never thought to use edges in a tangent mate (obviously!). Thank you SO much!!